The medium efficiency air filter is composed of artificial fibers and galvanized iron. There are various efficiencies to choose from, including 40-45%, 60-65%, 80-85%, 90-95%. The flange is made of 26 gauge galvanized iron. This series of products can be applied to air conditioning equipment in industrial, commercial, hospital, school, building, and various other factories. They can also be installed in gas turbine inlet equipment or computer rooms to extend the service life of the equipment.